Letter: Battling ‘Invasive Thugs’

The Nov. 2 article “Invasive Restrictions” by Michael Pope focused needed attention on the problem of exotic invasive plants overwhelming our parkland. At its October meeting, the Mount Vernon Council of Citizens’ Associations passed a resolution asking the Fairfax County Park Authority to prohibit vendors from selling exotic invasive plants at local farmers' markets. To create a "level playing field" for all businesses, the resolution also asks the Mount Vernon delegation to the General Assembly to introduce and support legislation to prohibit sale of exotic invasive plants by nurseries and garden centers. Current laws neither restrict their sale nor require them to be labeled as invasive. Many people mistakenly believe that, if a plant is for sale, it must be harmless.

Photo by Louise Krafft

A young, healthy sycamore was brought down by ivy growing almost to the top of the tree.

We hope that the state legislators quoted in the article will work with us to find a solution to this problem. Invaders such as English ivy, winter creeper, oriental bittersweet, Callery (Bradford) pear, wisteria, and bamboo, once planted in private yards, do not remain there. Because of their vigor and lack of natural controls, they escape into neighbors’ yards and nearby natural areas and replace the native vegetation, destroy trees, reduce the value of habitat to wildlife, and reduce biodiversity. According to renowned biologist E. O. Wilson, invasive species are the second greatest threat to biological diversity after habitat loss.

They cause economic as well as environmental harm, and pose hazards to public safety. English ivy, for example, creates habitat conducive to rats and to the spread of West Nile virus. Its weight makes trees hazardous and hides insect infestations. In the picture above, a young, healthy sycamore was brought down by ivy growing almost to the top of the tree. It took out a telephone pole as well as power, telephone, and cable lines. Luckily, it did not fall onto the house across Stockton Parkway in which four young children and their mother slept.

Restricting sale of non-native invasive plants will not be unduly onerous for vendors. The U.S. Fish and Wildlife Service lists 56 plant species as invasive in our region and 19 more as plants to watch. Few of these are currently sold in nurseries. Vendors could instead sell the beautiful and increasingly popular native plant species that attract birds and butterflies and enhance rather than harm the habitat in parks and yards, as well as the beautiful non-native plants that are not invasive and do no harm.

Until our legislators act, let the buyer beware. Homeowners, do not assume that plants sold commercially are harmless. To make sure that a plant that looks pretty in its pot in the nursery won’t be an invading thug, check the lists of invasive plants compiled by experts, such as U. S. National Fish and Wildlife Service’s Plant Invaders of Mid-Atlantic Natural Areas, at www.nps.gov/plants/alien/pubs/midatlantic/toc.htm) or the Virginia Department of Conservation and Recreation’s Invasive Alien Plant Species of Virginia, at www.dcr.virginia.gov/natural_heritage/invsppdflist.shtml.